Teens and their TV setsAccording to a Gallup Poll report, % of teens aged to have TVs in their rooms. Here is part of the footnote to this report:
These results are based on telephone interviews with a randomly selected national sample of teenagers in the Gallup Poll Panel of households, aged to . For results based on this sample, one can say . . . that the maximum error attributable to sampling and other random effects is percentage points. In addition to sampling error, question-wording and practical dif铿乧ulties in conducting surveys can introduce error or bias into the 铿乶dings of public opinion polls.
(a) We omitted the con铿乨ence level from the footnote. Use what you have learned to determine the con铿乨ence level, assuming that Gallup took an SRS.
(b) Give an example of a 鈥減ractical dif铿乧ulty鈥 that could lead to biased results for this survey.